Multiple rotary switch control



March 1, 1960 F. M. BROWN 2,927,168

MULTIPLE ROTARY SWITCH CONTROL Filed Feb. 19, 1957 k9 INVENTOR.

Franklin M Brown United States PatentO This invention pertains to electric switches, and relates particularly to novelcontrol mechanism for operating a plurality of-rotary switches and for indicating-the relative positions of said switches.

In many types of-electrical and electronicinst-ruments and equipment itis frequently required that relatively large numbers of switching adjustments be made for selecting proper values'of resistance, capacitance, or inductance. For example, in the operation of a rhcostat or voltage divider it is necessary frequently to make alarge number-of selections of resistance values in the search for-or setting ofa desired value.

It is a principalobject-ofthe present invention to pro- Vide a control by which a relatively large number of switching operations may beperformed from asingle dialing station. 7

Another important objectofthe present invention is the provision of a control mechanism 'foroperatinga plurality of switches selectively in any desired order by means of a single control knob.

A further important object-of the present invention is to provide a control mechanism for operating a; plurality of switches, which mechanism-is of compact and simplifiedconstruction for economical manufacture, which is readily adaptable for use with conventional type electric switches, and which is operable with speed and precision.

The foregoingand-other objects and advantages of the present inventionwill appear-from'the:following detailed description, taken in connection with the accompanying drawing, in-which:

Figure 1 is a-view-insideelevation ofa multiple switch control embodying the features of'the present invention, parts thereof being broken away to clisclose details of construction; and

'FigureZ is airagmentary planviewofthefront end of the control mechanism illustratedin Figure -1 and showing the read-out dial-assembly.

"The control assembly illustrated in the-drawing is mounted upon a frame assemblywhichincludes the main frame members 10 and l2 which are secured together in spaced relation by means of the connectingbolts 14 and spacersleeves 16. -A third framemember 18 is supportedbythe second frame member12in spaced relation to the latter by means-of'themounting bolts 20 and the plurality of pairs of spacer sleeves 22 24 and 26. These pairs of sleeves also serve to position elements of a switch assembly-in;spacedrelation intermediate the ends of the mounting bolts 20, as described more fully hereinafter.

Mounted upon the-third frame member 18, by means of the threaded hub 28 andsecuringlnut 30, is a housing 32-for a multiple switch-assembly. since the control mechanism illustrate'd in'the drawing is adapted particularlyffor use inth e assembling of voltage dividers or rheostats, the housing is shown to support a conventional continuous wire potentiometer resistance 34. Associated with said resistance is 'a'rotarycontact member 36 mounte,d upon-a rotary;shaft 38 whichextends through a central. bore in-the hub -28.

2,927,168 Patented Mar. 1, 1960 ice '2 An elongated tubular shaft 40 is secured at one end to the potentiometer contact shaft, as by means of a pin42, and extends freely through openings in the first and second frame members 10, 12. Mounted for longitudinal movement within the tubular shaft is a central shaft 44,

the outer endof which carries a control knob 46.

Mounted freely'pn the tubular shaft 40 for independent rotation is an elongated sleeve 48, the rearward end of which engages the rotary section 50 of a wafer switch.

The fixed section 52 of the wafer switch is mounted upon the mounting bolts '20 between the pairs '22, 24 of spacer sleeves. This fixed section carries a plurality of spaced mounting lugs 54 which are adapted to be engaged by one or more electrical contacts '56 mounted on the rotary section 50, in accordance with conventional practice. A detent support plate 58 is mounted upon the mounting bolts 20 between the pairs 24, 26 of spacer wafer switch makes positive electrical contact with a selected one or more of the mounting lugs 54.

The forwardend of the sleeve is serrated to provide a plurality of circumferentially spaced notches 68 adapted to receive a pin 70 which projects from the central shaft 44 through an elongatedslot 72 in the tubular shaft 40. Thus, when the central shaft is pushed rearwardly into the tubular shaft, the pin 70 engages one of the notches 68 in thesleeve 48, whereupon rotation of the control knob 46 causes rotation of the sleeve 43 and rotary sec tion 50 of the waferswitch.

Indicator means is provided for indicating the relative positions of the electrical contact 56 on the rotary section of the wafer switch with respect to the mounting lugs 54. In the embodiment illustrated in the drawing, such indicating means includes a transverse support-74 which is secured to the sleeve 48 an d whichcarries at its outer ends the supporting bolts 76 and sleeves-78. Mounted on the forward ends of the bolts and sleeves is an annular dial 80 which maybe graduated and marked appropriately to indicate therelative positions of the rotary and fixed sections-0f the wafer switch. Said dial assembly is mounted within the confines of the main frame members 10, 12 and the interconnecting sleeves 16, as illustrated in Figure 1.

Also mounted upon the tubular shaft 40 for indepen dent axial'rotation is a second sleeve 82, the rearward end of which is serrated toprovide a plurality of circumferentially spaced-notches 84 adapted to receive the projectingpin70. An intermediate-section of the sleeve engages the rotary section 86-of-a second wafer switch and the detent disc 88 associated therewith. The fixed section 90 of the wafer switch and the support 92 for detent spring 94 are supported from the first main frame first main frame member and is secured at its outer end to a fiat circular dial member 110 which may be graduated and marked in appropriate manner to indicate the relative positions of the rotary section 86 and fixed section 90 of the wafer switch.

The tubular sleeve projects forwardly through an opening in the dial member 110 and supports a third dial member 112 for rotation therewith. The third dial member overlies the second dial, and is smaller in diameter than said second dial. The third dial member is associated with the potentiometer unit, and since the latter generally functions, in a voltage divider or rheostat, as an interpolating resistance, the third dial is graduated and marked accordingly, as illustrated in Figure 2 With the pin 70 engaged in one of the notches 68 formed in the sleeve 48, rotation of the control knob 46 causes simultaneous rotation of the rotary section 50 of the first wafer switch. With the pin engaged in one of the notches 84 of the second sleeve 82, rotation of the control knob causes simultaneous rotation of the rotary section 86 of the second wafer switch. When the pin is positioned out of engagement with the notches in the sleeves, rotation of a control knob causes simultaneous rotation only of the contact arm 36 of the potentiometer unit. Means preferably is provided for securing the pin releasably in said three positions of adjustment. In the embodiment illustrated in the drawing, such means is provided by a hollow stud 114 projecting laterally from the tubular shaft 40. An opening in the tubular shaft registers with the hollow stud, and a ball 116 is mounted in said opening and urged resiliently toward the central shaft 44 by means of a coil spring 118 interposed between the ball and a cap screw 129 secured to the stud. Three longitudinally spaced annular grooves 122, 124 and 126 are formed in the central shaft 44 for selective reception of the ball 116. Thus, when the ball is seated in the forwardmost annular groove 122, the pin 70 will be retained within one of the notches 68 of the first sleeve 48. When the ball is retained in the intermediate annular groove 124, as illustrated, the pin will be positioned out of engagement with the notches of either of the sleeves. When the ball is retained in the rearwardmost annular groove 126, the pin will be secured in engagement with a notch 84 in the second sleeve 82.

As stated hereinbefore, the multiple switch control mechanism of the present invention is particularly adapted for use in the assembling of resistance elements into voltage dividers or rheostats. Such assemblies are made by mounting a plurality of fixed resistance elements between adjacent mounting lugs on each of the fixed sections of the wafer switches, to form a pair of series connected resistance chains. One or both ends of the potentiometer resistance then may be connected to selected ones of the fixed resistance elements mounted on the fixed section 52 of the wafer switch, by connection to the one or more electrical contacts 56 carried by the rotary section 50. Similarly, one or both ends of the series chains of resistances mounted upon the fixed section 52 of the first wafer switch may be connected selectively to one or more of the fixed resistances mounted upon the fixed section 90 of the second wafer switch, by connection to the one or more electrical contacts 104 carried by the rotary section 86. One or both ends of the resistance chain supported upon the fixed section 90 of the second wafer switch may be led outwardly through the space between the ring shaped dial member 80 and the second dial member 110, for connection to an external circuit.

From the foregoing it is believed to be apparent that the present invention provides a mechanical control by which the assembling and operation of multiple switches is accomplished with speed, facility and precision. The mechanical assembly is compact in design and thus accommodates installation in electric and electronic instruments with maximum facility. Selective operation of a plurality of multiple switches is achieved by operation of a single control knob, without longitudinal displacement of the indicating dials. This latter arrangement aifords maximum precision of dial reading.

It will be apparent to those skilled in the art that various details of construction described hereinbefore may be changed without departing from the scope and spirit of this invention. For example, it will be apparent that the potentiometer unit may be replaced by one of the wafer switch assemblies described and illustrated, and that other forms of switches may be utilized in the assembly with equal facility. These and other modifications may be made as desired, and therefore it is to be understood that the foregoing description is primarily illus trative of the invention and is not to be considered as limiting the scope thereof.

Having now described my invention and the manner in which the same may be used, what I claim as new and desire to secure by Letters Patent is:

1. A control for a plurality of rotary switch members, comprising a frame, a shaft mounted on the frame for axial rotation and for longitudinal displacement, a pair of rotary switch members mounted on the frame coaxial with and independently of the shaft and spaced apart with respect to the axis of the shaft, engagement means secured to the shaft and movable with the latter for selective engagement with each of the pair of rotary switch members one at a time for rotating the engaged rotary member simultaneously with the shaft, indicator dial means concentric with the shaft and associated with each rotary switch member, and connector means concentric with the shaft and interconnecting each indicator dial means and associated rotary switch member.

2. A control for a plurality of rotary switch members, comprising a frame, a shaft mounted on the frame for axial rotation and for longitudinal displacement, a pair of rotary switch members mounted on the frame coaxial with and independently of the shaft and spaced apart with respect to the axis of the shaft, engagement means secured to the shaft and movable with the latter for selective engagement with each of the pair of rotary switch members one at a time for rotating the engaged rotary member simultaneously with the shaft, indicator dial means associated with each rotary switch member, and connector means concentric with the shaft and interconnecting each indicator dial means and associated rotary switch member, a third rotary switch member mounted on the frame coaxial with the shaft, indicator dial means associated with the third rotary switch member and secured to the shaft for rotation therewith, and coupling means interconnecting the shaft and the third rotary switch member for rotating the latter simultaneously with the shaft while permitting longitudinal displacement of the shaft.

3. A control for a plurality of rotary switch members, comprising a frame, a hollow shaft mounted on the frame for axial rotation, a central shaft mounted slidably within the hollow shaft for axial rotation with and longitudinal displacement with respect to the latter, a pair of rotary switch members mounted-on the frame coaxial with and independently of the hollow shaft and spaced apart with respect to the axis of the hollow shaft, engagement means secured to the central shaft and movable with the latter for selective engagement with each of the pair of rotary switch members one at a time for rotating the engaged rotary member simultaneously with the central shaft, indicator dial means concentric with the hollow shaft and associated with each rotary switch member, and connector means concentric with the hollow shaft and interconnecting each indicator dial means and associated rotary switch member.

4. A control for a plurality of rotary switch members, comprising a frame, a hollow shaft mounted on the frame for axial rotation, a central shaft mounted slid- 5 ably within the hollow shaft for axial rotation with and longitudinal displacement with respect to the latter, a pair of rotary switch members mounted on the frame coaxial with and independently of the hollow shaft and spaced apart with respect to the axis of the hollow shaft, engagement means secured to the central shaft and movable with the latter for selective engagement with each of the pair of rotary switch members one at a time for rotating the engaged rotary member simultaneously with the central shaft, indicator dial means associated with each rotary switch member, connector means concentric with the hollow shaft and interconnecting each indicator dial means and associated rotary switch member, a third rotary switch member mounted on the frame coaxial with the hollow shaft, indicator means associated with the third rotary switch member and secured to the shaft for rotation therewith, and coupling means interconnecting the hollow shaft and the third rotary 6 switch member for rotating the latter with the central shaft while permitting longitudinal displacement of the shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,106,593 Swyers Aug. 11, 1914 1,743,357 Kita Jan. 14, 1930 1,753,505 Dyer Apr. 8. 1930 1,940,930 Wyman Dec. 26, 1933 2,501,415 Shampaine Mar. 21, 1950 2,603,725 Dietrich July 15, 1952 2,614,181 Consalvi et a1. Oct. 14, 1952 2,676,235 Kennedy et a1 Apr. 20, 1954 FOREIGN PATENTS 1,031,777 France Mar. 23, 19 

